Loading crane



June 1, 1954 c. H. WILLOWS 5 2,679,938

LOADING CRANE Filed July 14, 1950 3 Sheets-Sheet l INVENTOR. CL VDEk/ALLOWJ.

(-YTTOlE/VE 76 June 1, 1954 c. H. WILLOWS 2,679,938

LOADING CRANE Filed July 14, 1950 3 Sheets-Sheet 2 '62 as; in 57 59 63 ugi l INVENTOR. CLYDE H. WILLOWS 110 rams s.

June 1, 1954 c. H. WILLOWS I 2,679,938

LOADING CRANE Filed July 14, 1950 3 Sheets-Sheet 3 INVENTOR. CL YDE H.WILL 0W6.

ATTORNEYS- Patented June 1, 1954 LOADING CRANE Clyde H. Willows,Lakewood, Ohio, assignor to Cecil C. Peck Company, Cleveland, Ohio, acorporation of Ohio Application July 14, 1950, Serial No. 173,800

10 Claims. 1

This invention relates as indicated to a novel and improved crane and,more particularly, to a traveling lifting and loading deviceparticularly suited for the loading of heavy objects within trucks,vans, trailers, box cars and the like having roofs or covers normallyinterfering with loading operations wherein the load is suspended fromoverhead supporting means.

Various types of monorail conveyors are well known in the art and arefrequently employed to transport articles from place to place Within amanufacturing plant and also to and from the usual loading and unloadingdocks. It is customary to deposit the articles thus transported to aloading dock for shipment and then to manhandle the same into thewaiting truck trailer, box car, or the like. The disadvantages of thisprocedure are obvious but have been considered largely unavoidable. Itis frequently possible to deliver the articles to the loading dock forshipment much more rapidly than they can be stacked within the waitingvehicles so that congestion and inefficient handling results. The manuallabor involved is of the most strenuous sort and the risk of injury bothto the workers and to the articles being handled is considerable.

It is accordingly a primary object of my invention to provide a vehicleloading crane having an overhead support adapted to deposit a load wheredesired Within a covered vehicle and similarly to remove the sametherefrom, regardless of variation in height of such cover.

A further object is to provide a crane of the .type indicated alsoadapted to be suspended from an overhead monorail for travel therealong.

Still another object is to provide such crane mounted for a degree oflater swinging movement whereby loads may be raised and lowered frompositions to either side of the path of travel of such crane along itsoverhead monorail support.

A further object is to provide control means for such crane whereby asingle operator positioned adjacent the load to be transported maycontrol both the travel of the crane and the, raising and lowering ofthe load.

Other objects of my invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said inventionthen comprises the features hereinafter fully described and particularlypointed out in the claims, the following description and the annexeddrawing setting forth in detail certain illustrative embodiments of theinvention, these being indicative, however, of but a few of the variousways in which the principle of the invention may be employed.

In said annexed drawing:

Fig. 1 is a perspective view of my new crane shown in the act ofdepositing a load within a covered truck trailer, 2. portion of thelatter being broken away better to illustrate this operation;

Fig. 2 is a side elevational view of one preferred embodiment of thecrane of my invention;

Fig. 3 is a vertical sectional view taken along the line 33 on Fig, 2;

Fig. 4 is an enlarged vertical sectional View taken along the line 44 onFig. 2;

Fig. 5 is a top plan view of a preferred form of overhead supportingmeans for my new crane;

Fig. 6 is a wiring diagram of control means for operation of such crane;

Fig. 7 is a fragmentary side elevational view of the end of the craneboom modified for employment with a fork lift device;

Fig. 8 is an enlarged fragmentary elevational view of locking means forlocking the boom in position parallel to the central monorail support;

Fig. 9 is a detail sectional View taken along the line 99 on Fig. 8; and

Fig. 10 is a reduced diagrammatic plan view of a track system for suchcrane at a multiple loading dock or the like.

Referring now more particularly to said drawing and especially Figs. 1-5thereof, the embodiment of my invention there illustrated comprises arecurved hairpin boom including an upper horizontal arm l, a rigid,vertical elbow portion 2, and a relatively elongated, generallyhorizontal lower arm 3 adapted to be held rigid with such upper armportion. As best illustrated in Figs. 3 and 4, such boom may bedesirably of welded box frame construction comprising upper and lowerplates 4 and 5 respectively joined by side plates or web portions 6 andl. The dimensions of such side plates will ordinarily be increased inthe region of elbow 2, as illustrated, to ensure sufiicient strength andrigidity in this region of maximum strain, but the underside of upperarm I will ordinarily be generally parallel to the upper side of lowerarm or boom 3 when such lower arm is in horizontal position. A window 8is shown provided in such elbow portion 2 for a purpose to be explainedbelow.

This crane is adapted to be suspended from an overhead central monorail9 which is paralleled by two adjacent thrust rails It and H to eitherside thereof, the whole being suspended in the usual manner fromoverhead supports such as beams l2 and [3 or the like. Suspended fromthe center master rail 9 is a generally triangular carriage comprising atransverse member i4 and two legs or struts l5 and I6 joined at one endand at their other ends respectively connected with the extreme outerends of transverse member 14. A curved I-beam trackway i? is supportedby such carriage adjacent transverse member i l, having the point ofjoining [8 of such struts i5 and 16 as its center of curvature, suchcenter being directly beneath master rail 9 and also being the point ofattachment of upper boom arm i to such carriage by means of swivel 99,whereby the crane boom may be pivoted about a vertical axis. As bestshown in Figs. 2 and 3, such swivel mount 19, connected to carriagestrut members it and I6, is also provided with two pair of suspensionrollers 29 adapted to travel along the lower flanges of master rail 9.Such swivel and rollers are designed to support the entire weight of thecrane and any load carried thereby. Such swivel l9 may desirably belocated approximately midway of the length of upper arm i, such upperarm in turn extending about the length of lower boom arm 3. Wherever twopair of rohers are employed in association, they should also be providedwith swivel mounts to facilitate travel around curves.

The forward end of arm I is also provided with a swivel 2i carryingrollers 22 adapted to rest upon and travel along the lower flange ofI-beam arcuate trackway I1. The hairpin boom is thus steadied andsupported when swung from side to side about its main pivot or swivel59, the degree of such swinging movement being limited by engagement ofrollers 22 with the carriage side strut members and I5 (see diagrammaticFig. 5). Brace rollers 23 and 24 are carried by the extreme outer endsof transverse member is and are adapted to bear upwardly against theundersides of the respective thrust rails l9 and il. Accordingly, whenthe crane boom is swung to one side as shown in Fig. 5, for example,tipping of the supporting carriage frame is prevented.

One or more monorail tractors such as 25 and 26 of standard design maybe suspended from the lower flange of master rail 9 and connected to theforward nd of the boom supporting cari riage which is likewise suspendedfrom the lower flange of such monorail by means of rollers 27. It willthus be seen that the boom supporting carriage is suspended from themaster rail both in the region of swivel ill by rollers and at theforward end of such carriage by rollers 21. Such spaced points ofsuspension together with the provision of the laterally spaced bracerollers 23 and 24 adapted to engage the undersides of thrust rails I0and H respectively aiford a maximum degree of support and stability.Tractors 25 and 26 are mounted to drive the crane supporting carriage ineither direction along such overhead trackway.

Work lifting means is provided, normally at the extreme forward end oflower boom arm 3. As illustrated in Figs. 1-5 inclusive, such means maycomprise a conventional Yale & Towne chain hoist 23 suspended in window8 and including the usual electric motor driven reel or winch and chainstorage pocket P from which the chain is paid out and into which it maybe withdrawn by operation of such winch. The chain 29 may be broughtdown beneath a sprocket 38 within elbow portion 2 of the boom and thenconducted over a series of supporting sprockets 3! to the forward end ofboom arm 3 where it is secured at 32 to the underside of downwardlyinclined guard end 33 of such boom. A hook 34 is shown suspended byblock 35 in a loop 35 of such chain 29. Since ordinarily it will only benecessary to lift a load a relatively short distance to raise the samefrom the floor and to clear minor obstacles, there is ordinarily no needto provide hoisting means adapted to accommodate a great deal of chainor cable.

Now referring more especially to Fig. 7 of the drawing, an alternativelifting means is there illustrated in side elevation, comprising astandard fork lift 31 mounted on the end of boom arm 3 and adapted to bereciprocated up and down in the usual manner by means of fluid pressurepiston-cylinder assembly 38. Such fork and its supporting means 39 willdesirably be mounted for pivotal adjustment about a horizontal axis 40transverse of such boom, being tilted into desired adjusted position bymeans of small fluid pressure piston-cylinder assembly M. A pump 42driven by an electric motor 43 may be conveniently attached to theunderside of boom arm 3 adjacent such fork lift to supply fluid pressureto piston-cylinder assembly 38. Likewise, a reservoir (not shown) ofhydraulic fluid may conveniently be contained within such boom armtogether with the usual conduits (likewise not shown). It will, ofcourse, be understood that a variety of lifting means may be providedfor the purpose of elevating a load relative to boom arm 3 in additionto the typical examples illustrated and described. In fact, since, asindicated, it is ordinarily only necessary to elevate a load a shortdistance from the floor, a manual chain hoist may be secured to the endof the boom for such purpose. Ordinarily, however, powered lifting meanswill be preferred.

When the crane is traveling along its trackway, down an aisle within aplant, for example, it is important that the boom be maintained parallelto the master rail 3 from which it is sus pended and that it shall notslew from side to side about its swivel 19. Accordingly, as best shownin Figs. 1, 8 and 9, a lock means is provided on upper boom arm iadapted to be engaged with appropriate retaining means on arcuatetrackway I1 directly below master rail 9. In the form illustrated inFigs. 8 and 9, two spaced lugs -44 and 45 are welded to the lower flange45 of track member 1! closely adjacent the vertical web portion thereof.A latch member t] is horizontally pivotally mounted at 48 in a frame 49on upper boom arm i. A solenoid armature 59 is pivotally connected tosuch latch by means of link members 5| whereby such latch may be raisedto disengage the same from between looking lugs 44 and 45 byenergization of solenoid coil 52. It will thus be seen that when theboom is brought into parallel alignment with master rail 9 it will belocked in such position, preventing swinging of the same relative to itssupporting carriage. When the operator desires to pick up a loadadjacent an aisle along which the crane is travelling, for example, hewill stop the crane, disengage the look by energizing solenoid 52 andthen manually swing the boom to the side desired. After raising the loadfrom the floor, the boom will again be swung into position parallel tomaster rail 9 and locked in such position for continued travel.

Referring now to Fig. 6 of the drawing, there is there illustrated atypical wiring diagram for control and operation of the crane shown inFig. 2, for example. Power to energize the various tractor and hoistmotors is taken from the usual monorail trolley wires 53 by the usualcollectors 54. The reversible tractor motors 55 (only one being shown inthis diagram, it being understood that any desired number of tractorsmay be employed) may be energized in the usual manner as by pressingforward push button 56 or reverse push button 57. Similarly, reversiblehoist motor 58 may be energized to take in chain 29 by pressing button59 and to pay out such chain by pressing button 60. A normally closedhoist limit switch 81 may desirably be provided (see also Fig. 2) whichwill automatically be opened by operation of control lever 62 when block35 has been elevated to its uppermost position, thereby de-energizinghoist motor 58. The latch solenoid 52 is controlled by push button 82,the operator holding the push button in to complete the circuit toenergize such solenoid when he wishes to disengage the latch 41. Asshown in Fig. 2, such push button controls will desirably be locatedadjacent the end of lower boom arm 3 and preferably on the undersidethereof, a guard 63 being provided to prevent possible damage thereto.

Unfortunately, as a practical matter, the height of covered vans and boxcars varies considerably whereas the overhead trackway, once installed,is fixed at a definite elevation. To be commercially acceptable, theloading means must be adapted to enter all such covered vehicles incommon use. Merely to employ a longer elbow portion 2 with lower boomarm 3 extending fixedly, rigidly therefrom is not a solution to thisproblem since it then becomes impossible to utilize the extra space inthe upper portion of the higher vans. Neither has it been foundsatisfactory to mount the entire hairpin boom for raising and loweringrelative to such trackway since this obviously will necessitateelaborate mechanism for such purpose if the desired structural rigidityis to be maintained. The lower boom arm should also, of course, beadapted for insertion of sub-- stantially its entire length within thevehicle.

To solve this difiiculty in a practicable manner, I secure lower boomarm 3 to the downward- 1y extending portion 2 by means of a horizontalpivot $4 permitting up and down swinging adjustment of such boom arm 3in the vertical plane including upper boom member I. Such upper andlower boom members are respectively provided with rearward extensions 65and 66 with a screw jack interposed therebetween. Such jack comprises ascrew 6'! one end of which is threadedly engaged in a socket 68 in upperextension 65 and the other end of which is rotatably engaged in a swivelsocket in sliding mount 69 in lower extension 86 permitting the same toaccommodate itself to varying degrees of inclination. A transverse holeIll through such screw permits insertion of a turning rod or handle. Alarge lock nut H serves to lock such jack in adjusted position. Sincethe outer end of boom arm 3 will ordinarily be maintained at a singleselected elevation during loading of any particular car or van, jack 5']will require only occasional adjustment. Furthermore, since arm 3 ismuch longer than its rearward extension 66, a relatively slightadjustment of jack 6? is correspondingly magnified at the extreme end ofboom arm 3. Obviously, various equivalent adjustably extensible meansmay be employed instead of such screw jack, including a fluid pressureactuated pistoncylinder assembly. for example, pivotally interconnectingextensions 65 and 66.

Referring now more particularly to Figs. 1 and 10 of the drawing, theoperation of my new crane may be explained as follows. Assuming that aheavy crated load is to be transported from the work floor of a plant toa waiting van or truck trailer, for example, the operator will firstpress either the forward button 56 or the reverse button 5! to energizethe tractor motor or motors to cause the crane to travel to a pointwhere the end of lower boom arm 3 is adjacent the load. The operatorthen stops the tractor motor and presses push button 62' to disengagelatch 5? and permit him to swing the boom until hook at is above theload. He then presses hoist motor control button 6|] to lower block 35and hook until such hook can be engaged to the load. Push button 59 isnow pressed to reverse hoist motor to raise the load the necessarydistance from the floor to ensure that all minor obstacles such as sillsand the like will be cleared. When the boom has been swung back intoparallel with master rail 9 and latched in such position (locking lugs44 may be provided with beveled edges as shown in Fig. 9 to cam latch Mupwardly, thereby causing the latter automatically to enter intolatching position between such lugs when the boom is swung), theoperator will now press forward push button 56 to cause the tractors tomove the crane toward the loading dock, it being understood that thecrane supporting carriage will be mounted on the trackway with theforward end of lower boom arm 3 directed toward such dock. Due to theconvenient positioning of the control buttons, the operator may walkalongside the crane closely adjacent the load, with such crane and loadunder immediate control at all times. He is thus enabled to avoidobstacles and pass the load through openings where there is but smallclearance with the greatest of ease. The trackway will extend out overthe loading dock and somewhat beyond, as shown in Fig. 1, so that lowerboom arm 3 may enter and reach to the forward end of a van or trailerparked therebeneath. The operator will enter the van with the load,stopping the tractor motor when such load has reached the desiredposition. If necessary, he may disengage the latch and swing the boomslightly to one side or the other in order to position the load exactlyas desired. He will then press button as to cause the hoist to lower theload to the trailer floor whereupon hook 34 may be disengaged and thecrane now backed away.

While lower boom 3 may be swung upwardly about its pivot fi l after aload has been raised by the hoisting means, it is obviously ordinarilypreferable to make such adjustment in advance. When boom 3 is inhorizontal position, it will be designed to enter the lowest roofedvehicles it is desired to load. Consequently, all normal adjustmentsthereof will be to raise the end of such boom rather than to lower thesame below a horizontal position. This means that there will never beany problem of the boom encountering the roof of the vehicle after ithas been partially inserted within the latter.

As diagrammatically illustrated in Fig. 10, the trackway comprising theparallel rails 9, l0, and ii may terminate in a separate segment llmounted for lateral travel along transverse rails 72 and 13. When my newcrane has been conducted onto such segment (in alignment with the maintrack rails), such segment and crane may then be shifted laterally alongloading dock 14 as required to load any selected vehicle. Furthermore,when it is desired to deposit a load within the ends of a box car, forexample, the end of the boom may first be inserted through the doorwayand the track segment then shifted somewhat laterally so that the boomend may swing into the end of the car. Such track segment may be carriedby the usual overhead traveling crane. It will be appreciated thatarcuate trackway Il may comprise any desired part of a circle, even afull 360, if desired, in order to permit the requisite swinging movementof the boom for any particular installation.

By employing the crane of my invention it is possible to load heavypackaged materials, for example, in covered vehicles with ease wherepreviously considerable man-power was required. With heavy itemsnecessitating the use of a crane it was formerly customary to load thesame on flat-cars or open trailers, exposed to the Weather. Certainarticles such as rolls of carpet, long bundles of bar stock, etc., canbe loaded into box cars without difiiculty whereas lift-trucks and theusual cranes have proven unequal to the job. By providing for upwardswinging adjustment of the lower boom member I am enabled to take fulladvantage of the height of the vehicle both to load large objects and tostack articles therein. Instead of mounting my rane on a monorail systemsuch crane may be mounted directly on the carriage of a two-waytraveling overhead crane in the same manner in which it is mounted onthe monorail carriage, and may then be employed to load box cars asdescribed above.

Other modes of applying the principle or" the invention may be employed,change being made as regards the details described, provided thefeatures stated in any of the following claims or the equivalent of suchbe employed.

I therefore particularly point out and distinctly claim as my invention:

1. A traveling loading crane comprising an upper horizontal boom member,a member extending downwardly from said boom member adjacent one endthereof and rigid therewith, a lower boom member generally parallel tosaid upper boom member and pivotally connected adjacent one end to saiddownwardly extending member for up and down swinging movement in a planeincluding said upper boom member, adjustable brace means interconnectingsaid two boom members adjacent such pivot adapted to regulate theinclination of said lower boom member relative to said upper boommember, and work lifting means on the extended end of said lower boommember adapted to lift such work relative to such lower boom end.

2, A traveling loading crane comprising a carriage, an upper horizontalboom member suspended from said carriage for swinging movement about arigid vertical axis, a member extending downwardly from said boom memberadjacent but spaced from one end thereof and rigid therewith, arelatively short extension of said boom member projecting therebeyond, alower boom member generally parallel to said upper boom member andpivotally connected adjacent one end to said downwardly extending memberfor limited up and down swinging movement in a plane including saidupper boom member, said lower boom member also having a relatively shortextension projecting in the opposite direction beyond such pivot belowand parallel to said short extension or said upper boom member, jackmeans interposed between said extensions and operative to rock saidlower boom member about such pivot adjustably vertically to position theextreme loadlifting end of said lower boom member, and load liftingmeans on the end of said lower boom member adapted to elevate such loadrelative to said lower boom member.

3. In a loading crane adapted to be suspended from an overhead trackway,a carriage adapted to travel along such trackway, an upper horizontalboom member suspended from said carriage for swinging movement about arigid vertical axis, an arcuate trackway on said carriage having suchaxis for a center, boom-supporting means on said boom and engaging saidarcuate trackway for travel therealong when said boom is swung aboutsuch axis, a member extending downwardly from said boom adjacent butspaced from one end thereof and rigid therewith, a relatively shortextension of said boom projecting therebeyond, a lower boom membergenerally parallel to said upper boo-m member and pivotally connectedadjacent one end to said downwardly extending member for limited up anddown swinging movement in a plane including said upper boom member, saidlower boom member also having a relatively short extension projecting inthe opposite direction beyond such pivot below and parallel to saidshort extension of said upper boom member, jack means interposed betweensaid extensions and operative to rock said boom member about such pivotvertically ad- J'ustably to position the extreme load-lifting end ofsaid lower boom, hoisting means on the end 01 said lower boom, drivemeans for said hoistin, means at least partially enclosed within suchboom structure operative to raise and lower said hoisting means relativeto said lower boom, and manual control means for said drive means onsaid lower boom.

4. In a loading crane adapted to be suspended. from an overheadtrackway, a carriage adapted to travel along such trackway, tractormeans operative to drive said carriage along such tract: way, an upperhorizontal boom member sus-- pended from said carriage for swingingmovement about a rigid vertical axis, an arcuate trackway on saidcarriage having such axis as a center, boom-suspending means on saidboom and engaging said arcuate trackway for travel there" along whensaid boom is swung about such axis, a member extending downwardly fromsaid boom adjacent but spaced from one end thereof and rigid therewith,a relatively short extension of said boom projecting therebeyond, alower boom member generally parallel to said upper boo-m member andpivotally connected adjacent one end to said downwardly extending memberfor limited up and down swinging movement in a plane including saidupper boom member, said lower boom member also having a relatively shortextension projecting in the opposite direction beyond such pivot belowand parallel to said short extension of said upper boom member, jackmeans interposed between said extensions and operative to rock said boommember about such pivot vertically adjustably to position the extremeloadlifting end of said lower boom, hoisting means on the end of saidlower boom, drive means for said hoisting means at least partiallyenclosed within such boom structure operative to raise and lower saidhoisting means relative to said lower boom, and manual control means forsaid tractor means and said hoist drive means on said lower boom.

5. A traveling loading crane comprising a carriage adapted to travelalong an overhead trackway, a generally C-shaped boom structuresuspended from said carriage by means of a rigid vertical pivot on theupper generally horizontally extending portion of said structureintermediate the ends thereof, the lower generally horizontallyextending portion of said structure being pivotally connected to theremainder of said structure for up and down swinging adjustment relativethereto, means extending from said upper boom portion to said lower boomportion without obstructing the space between said upper and lower boomportions to hold said lower boom portion in selected adjustedinclination relative to said upper boom portion, and lifting means onthe free end of said lower boom portion operative to elevate a loadrelative thereto.

6. A traveling loading crane comprising a carriage adapted to travelalong an overhead trackway, a generally horizontally disposed elongatedupper boom member mounted on the underside of said carriage intermediatethe ends of said boom for swinging movement about a rigid vertical axis,a lower boom member pivotally connected to and downwardly spaced fromsaid upper boom member adjacent one end for up and down swingingmovement, whereby the other end of said lower boom may be adjustablypositioned at a desired elevation, lateral brace means on said carriageadapted to engage an overhead abutment and thereby brace said carriagewhen said boom members are swung laterally of such trackway, supportingmeans on said carriage adapted to engage and support an end of saidupper boom in all lateral swinging positions of the latter, and liftingmeans on the extended end of said lower boom operative to lift a loadrelative thereto.

7. A loading crane comprising a generally C-shaped boom structure,traveling overhead supporting means for said boom structure suspendingthe latter by means of a rigid vertical pivot on the upper generallyhorizontal portion of said structure, the lower generally horizontallyextending portion of said structure being pivotally connected to theremainder of said structure for up and down swinging adjustment relativethereto, means extending from said upper portion to said lower portionwithout obstructing the space within such to hold said lower boomportion in selected adjusted position, supporting means on said upperboom portion spaced from such vertical pivot and adapted to support saidboom structure to prevent bending action on such vertical pivot underload, and lifting means on the free end of said lower boom operative tolift a load relative thereto.

8. In a loading crane adapted to be suspended from an overheadtraclrway, a carriage adapted to travel along such trackway, an upperhorizontal boom member suspended from said carriage for swingingmovement about a rigid vertical axis, an arcuate trackway on saidcarriage having such axis as a center, boom supporting means on saidboom member and engaging said arcuate trackway for travel therealongwhen said boom member is swung above such axis, a member extendingdownwardly from said boom member adjacent one end thereof and rigidthere-with, a lower boom member generally parallel to said upper boommember and p-ivotally connected adjacent one end to said downwardlyextending member for up and down swinging movement in a plane includingsaid upper boom member, adjustable brace means interconnecting said twoboom members adjacent such pivot adapted to regulate the inclination ofsaid lower boom member relative to said upper boom member, and worklifting means on the extended end of said lower boom member adapted tolift such work relative to such lower boom end.

9. A traveling loading crane comprising a carriage adapted to travelalong an overhead trackway, a generally c-shaped boom structure havingupper and lower boom portions which extend generally horizontallybeneath said carriage, support means extending downwardly from saidcarriage and engaging the generally horizontal upper :portion of saidboom structure at longitudinally spaced apart points there-along, saidsupport means mounting said boom structure for swinging movement about avertical axis, the generally horizontal lower portion of said boomstructure being pivotally connected for vertical swinging adjustmentrelative to said upper boom portion, means extending between such upperand lower portions operative to hold said lower boom portion in selectedadjusted position, and load engaging means on said lower boom portion.

10. A traveling loading crane comprising a carriage, a horizontal upperboom member suspended from said carriage for swinging movement about avertical axis, boom-supporting means extending from said carriage tosaid upper boom member at a point spaced from said axis operative toprevent bending action of said upper boom member under load, a memberextending downwardly from said upper boo-m member adjacent one endthereof, a lower boom member generally parallel to said upper boommember and pivotally connected to such downwardly extending member forup and down swinging movement, adjustable brace means interconnectingsuch boom members adjacent such pivot adapted to regulate theinclination of said lower boom member relative to said upper boommember, and work engaging means on the extended end of said lower boommember.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 428,301 Forter May 20, 1890 437,819 Morgan Oct. '7, 1890744,316 Eitle Nov. 17, 1903 854,837 Paige May 28, 1907 1,521,266 AndrewsDec. 30, 1924 1,546,364 Bennington July 21, 1925 1,720,240 Saborsky July9, 1929 1,783,021 Leach Nov. 25, 1930 2,322,636 Kidder June 22, 19432,546,362 Graham Mar. 27, 1951 FOREIGN PATENTS Number Country Date256,568 Germany Feb. 15, 1913

